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Whenever fall and winter come around, do you feel unhappy for no real reason? Like millions of other people around the world, you might be experiencing seasonal affective disorder, also known by its acronym, SAD.

Medical experts theorize that when symptoms of depression start in September and vanish in May, they may be caused by a lack of sunlight.  During spring and summer, days are longer, allowing us to spend more time in the sun. During that time, the sun’s radiant energy boosts our mood, improves our sleep habits, and stimulates the production of Vitamin D in our bodies, which in turn supports our immune system. But when days grow shorter, we miss the health benefits of those powerful solar rays.

To counteract the effects of SAD, some doctors suggest light therapy. That simply means sitting in front of a light box—a high-intensity fluorescent lamp—for at least 30 minutes a day. Theoretically, regular exposure to bright light will cheer a SAD person, even on the darkest winter day.


Photo: Wonderlane / CC-BY-SA-3.0

When doctors “theorize,” they

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